The high rates of production by planktonic bacteria reported by Sorokin for the warm surface layer of the oceans cannot be reconciled with the geographic distribution of dissolved organic carbon. These rates, as well as Sorokin's figures of bacterial production and, hence, consumption of oxygen in the deep sea are too high by an order of magnitude. It is left undecided whether the principal sink for the dissolved organic matter reaching the deep sea is in the warm surface layer of the oceans, as suggested by Sorokin, or the deep sea itself.